Single Skin Cover 6 Corrugated Sheeting
The following details are a guide to aid during the installation of single skin sheeting, it is not meant to be a definitive guide as many different factors can contribute to the fixing of sheets.
Sealants & Fixings
- Number Of Fixings Per Sheet It is recommended that 3 fixings per sheet width per purlin are used. At the eaves it is recommended that additional fixings are used.
- Side Lap Stitching The side laps should be stitched at maximum 450mm centres (if required).
- Side & End Lap Sealing Both the side and end laps should be sealed using a 6mm x 5mm butyl mastic.
- Main Fixings For the roof a corrugated (sinusoidal) sheet should always be fixed through the crest of the sheet and should incorporate an M6 or M8 sealer washer (dependent on purlin material). The head of the fixing should ideally then be covered using a shallow or deep cap (option not available for all fixings). For a wall the above installation can be utilised, however some people may prefer to use a standard fixing with a 16mm or 19mm moulded head but be aware that the washer may not form a fully water tight seal.
- Side Lap Fixings The side laps can be sealed using stitcher fixings or rivets.
- Rooflight Fixings Any rooflights should be fixed in the same manner as the main sheeting, however the side laps must be sealed using rubber sleeved ‘Lapfix’ fixings and not stitchers.
- Purlin Spacings As the maximum purlin spacing for fibre cement sheeting is 1375mm these centres are more than suitable for the Cover 6 steel sheet, however because it is a steel sheet the purlin spacing can be as much as 1800mm when installed with no fibre cement present.
Installing Fibafix / Black Sealer Washers
Special care and consideration needs to be taken with fibre cement, asbestos & Cover 6 sheets that are installed beyond a 15° pitch. Holding clips should be used to ensure that the weight of the sheet is not transferred to the fastener. As with all instances where contact with asbestos is likely, special health and safety considerations need to be taken into account. When drilling through asbestos type materials, it is likely that asbestos fibres will be released which can lead to ill health. Precautions should always be taken to protect the operative and any other person that may be affected by operations such as site visitors and the public. Current legislation should always be followed and risks assessed and controlled.
The diagram below shows the correct installation when using a fixing with a sealer washer.